EP0950125B1 - Verfahren zur herstellung eines diamantbeschichteten gegenstandes und dabei erhaltenes produkt - Google Patents

Verfahren zur herstellung eines diamantbeschichteten gegenstandes und dabei erhaltenes produkt Download PDF

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Publication number
EP0950125B1
EP0950125B1 EP97938573A EP97938573A EP0950125B1 EP 0950125 B1 EP0950125 B1 EP 0950125B1 EP 97938573 A EP97938573 A EP 97938573A EP 97938573 A EP97938573 A EP 97938573A EP 0950125 B1 EP0950125 B1 EP 0950125B1
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Prior art keywords
substrate
weight percent
temperature
diamond
resintering
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French (fr)
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EP0950125A1 (de
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Yixiong Liu
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Kennametal Inc
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Kennametal Inc
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C5/00—Milling-cutters
    • B23C5/02—Milling-cutters characterised by the shape of the cutter
    • B23C5/10—Shank-type cutters, i.e. with an integral shaft
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/02—Pretreatment of the material to be coated
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/24—After-treatment of workpieces or articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B51/00—Tools for drilling machines
    • B23B51/02—Twist drills
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
    • B23P15/28—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass cutting tools
    • B23P15/32—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass cutting tools twist-drills
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
    • B23P15/28—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass cutting tools
    • B23P15/34—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass cutting tools milling cutters
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C1/00—Making non-ferrous alloys
    • C22C1/04—Making non-ferrous alloys by powder metallurgy
    • C22C1/05—Mixtures of metal powder with non-metallic powder
    • C22C1/051—Making hard metals based on borides, carbides, nitrides, oxides or silicides; Preparation of the powder mixture used as the starting material therefor
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/02—Pretreatment of the material to be coated
    • C23C16/0209—Pretreatment of the material to be coated by heating
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
    • C23C16/26—Deposition of carbon only
    • C23C16/27—Diamond only
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
    • C23C30/005—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process on hard metal substrates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B2228/00—Properties of materials of tools or workpieces, materials of tools or workpieces applied in a specific manner
    • B23B2228/10—Coatings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C2226/00—Materials of tools or workpieces not comprising a metal
    • B23C2226/31—Diamond
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12014—All metal or with adjacent metals having metal particles
    • Y10T428/12028—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
    • Y10T428/12146—Nonmetal particles in a component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
    • Y10T428/12826—Group VIB metal-base component
    • Y10T428/1284—W-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/30—Self-sustaining carbon mass or layer with impregnant or other layer

Definitions

  • CVD chemical vapor deposition
  • the application of an adherent CVD diamond coating to a member should provide a member with excellent characteristics.
  • CVD diamond coating there has been at least one drawback with the application of a CVD diamond coating to the substrate; namely, the inability to consistently maintain the dimensional integrity of certain substrate geometries prior to the application of the CVD diamond coating. This results in a failure to consistently produce diamond-coated, tight tolerance members that have dimensional integrity.
  • One consequence for example, is the inability to use an elongate cutting member to consistently drill holes to a high dimensional accuracy.
  • the first step comprises forming a green body of a partial density from a homogeneous mixture of powder components.
  • the next step comprises consolidating the green body under heat or heat and pressure (e.g., sintering such as, for example, vacuum sintering, pressure sintering or hot isostatic pressing) to form a consolidated or sintered substrate with full density.
  • sintering such as, for example, vacuum sintering, pressure sintering or hot isostatic pressing
  • the next step may comprise grinding, i.e., removing material from, the sintered substrate so as to define the structural features of the elongate cutting member.
  • grinding typically smears cobalt on the surface of the as-ground sintered substrate which adds to the surface cobalt already present due to the wettability of the tungsten carbide by the cobalt under vacuum sintering conditions.
  • the next step comprises resintering the as-ground substrate.
  • International Patent Application No. PCT/US94/02346 describes a resintering process in which the resintering results in a surface with a lower cobalt content and an increased substrate surface roughness. More specifically, the substrate is resintered under time, temperature and atmospheric conditions so as to cause grain growth and binder evaporation from the surface of the substrate.
  • the time and temperature are selected so that sufficient abnormal or exaggerated grain growth occurs on the surface of the substrate to achieve a surface roughness, R a , of greater than 0.635 mm (25 microinches), R a , preferably greater than 0.762 mm (30 microinches), R a , and most preferably at least 1.016 mm (40 microinches), R a .
  • the resintering may be performed at 2750 °F (1510 °C) for two to three hours in about 66.7 Pa (0.5 torr) nitrogen atmosphere.
  • the sintering time will depend upon the composition of the substrate and the resintering conditions. It is typically the case that as the sintering temperature increases the sintering time decreases. If the surface roughness is not sufficient after the first resintering, the substrate may be subjected to a subsequent resintering.
  • the nitrogen partial pressure should be controlled so as to allow the cobalt to evaporate from the surface of the substrate. Yet, there should be a minimal re-wetting of the surface of the substrate by cobalt from the bulk region of the substrate while avoiding any noticeable formation of a nitride layer on the substrate surface. It is typical that the selected nitrogen partial pressure is between 40 Pa and 667 Pa (0.3 torr and 5 torr).
  • U.S. Patent No. 5,403,628 (an equivalent to International Publication No. WO92/09722) uses a process that includes the post-grinding steps of a nitrogen treatment followed by a vacuum treatment. The combination of the nitrogen and vacuum treatments appear to result in a substrate with a surface region having an increase in binder content and a reduction in the mixed carbide content.
  • European Patent Application No. 0 246 211 concerns a process for making a cutting insert that includes the steps of sintering, grinding, thermal treating at a temperature greater than the liquid phase sintering temperature, and coating. European Patent Application No.
  • 0 374 923 pertains to the production of a cemented carbide cutting insert by a process that includes the steps of: sintering, grinding, heat treating, chemical etching and coating. The purpose of the heat treatment is to produce a substrate with two diffraction peaks.
  • U.S, Patent No. 5,250,367 discloses a process to make a coated cutting insert. The process includes the steps of sintering, grinding (or honing), resintering and coating.
  • the applicant has found that the as-ground substrate experiences dimensional distortion upon resintering. He believes that one factor that aggravates the distortion has to do with the residual stresses caused during the grinding operation. More specifically, the grinding of the sintered substrate introduces residual stresses to the as-ground substrate. These residual stresses then aggravate the dimensional distortion of the substrate upon resintering at a temperature above the liquidus.
  • a high aspect ratio substrate is one wherein the ratio of the major dimension (e.g., the length or the diameter depending upon the geometry of the substrate) to the minor dimension (e.g., the diameter or the thickness, respectively) is high such as, for example, greater than 10:1.
  • the resintered substrate is then coated with diamond using CVD techniques to form a diamond-coated elongate cutting member.
  • the substrate temperature during coating be maintained between 700 °C and 875 °C. If the temperature is below 700 °C, too much graphite forms in the diamond coating which significantly reduces the wear resistance. At a temperature below 700 °C, there is a reduction in the deposition rate of the coating. If the temperature is above 875 °C, too much cobalt diffuses from the substrate during the coating operation so as to adversely affect the adhesion of the coating to the substrate.
  • these diamond-coated high aspect ratio members may have significant dimensional distortion because the substrate underwent dimensional distortion during resintering. Dimensional distortion in a diamond-coated elongate cutting member, for example, is an undesirable characteristic. It would thus be very desirable to provide a method of making a diamond-coated member, as well as the member itself, wherein the diamond-coated member exhibits a high degree of dimensional integrity along with an adherent CVD diamond coating.
  • the invention is a method of making a diamond-coated elongate cutting member comprising the steps of: providing a sintered substrate that includes hard grains bonded together by a metallic binder wherein some of the binder may be at the surface of the substrate; grinding material from selected portions of the sintered substrate so as to form an as-ground substrate having residual stresses caused by the grinding; annealing the as-ground substrate at a temperature below the liquid phase sintering temperature so as to reduce the residual stresses so as form an annealed substrate; resintering the annealed substrate at a temperature above the liquid phase sintering temperature so as to coarsen the size of the hard grains at the surface of the annealed substrate so as to form a resintered substrate with a roughened surface; and coating the resintered substrate with a diamond coating by chemical vapor deposition.
  • FIG. 1 illustrates a twist drill 10 which has an axially forward end 12 and an axially rearward end 14.
  • Twist drill 10 has a rearward shank 16 which presents a relatively constant diameter.
  • Twist drill 10 has a fluted portion 13.
  • Twist drill 10 also has at least one cutting edge 22 at the axially forward end 12 thereof.
  • a shoulder 20, which has a frusto-conical shape, provides the transition between the fluted portion 18 and the rearward shank 16.
  • the diameter of the rearward shank 16 is larger than the diameter of the fluted portion 18.
  • Twist drill 10 has an adherent diamond coating on its cutting edge 22 and on at least a portion of the fluted portion 18.
  • FIG. 2 illustrates an end mill 30 which has an axially forward end 32 and an axially rearward end 34.
  • End mill 30 also has a rearward shank 36.
  • End mill 30 also has a fluted portion 38.
  • End mill 30 has an adherent diamond coating on its cutting edges and on areas adjacent to them.
  • the twist drill and the end mill are representative, but not all inclusive, of high aspect ratio members to which this invention pertains.
  • the invention includes other high aspect ratio member such as, for example, reamers, taps, routers, borers, end mills, thread cutting end mills, and seal rings.
  • the first step comprises providing a mixture of powder components that form the composition of the substrate.
  • these components are blended by ball milling or the like into a homogeneous powder mixture.
  • These powder components typically comprise hard grains (e.g., tungsten carbide) and a metallic binder (e.g., cobalt).
  • the powder blend is then formed into a green body of an elongate shape.
  • the green body has a partial density.
  • the typical forming process comprises extrusion.
  • the green body is then consolidated under heat or heat and pressure to form a substrate of full density.
  • Exemplary consolidation processes involving liquid phase sintering include vacuum sintering, pressure sintering, and hot isostatic pressing.
  • the consolidation process may comprise liquid phase vacuum sintering at a temperature of about 2750 °F (1510 °C) for a duration of about three hours.
  • the result is the formation of a generally cylindrical sintered substrate blank for the twist drill.
  • Cobalt is typically present at the surface of the sintered substrate due to the wettability of the tungsten carbide by the cobalt.
  • the next step is to grind the sintered substrate to form the flutes, the cutting edges, and other structural features of the twist drill. It is during the grinding that cobalt is smeared across the surface of the as-ground substrate. The grinding step also introduces residual stresses into the as-ground substrate. After completion of the grinding process, the as-ground substrate has a surface with excessive cobalt thereon due to the grinding as well as the wettability of the tungsten carbide by the cobalt.
  • the as-ground substrate is subjected to an annealing step.
  • the as-ground substrate is preferably heated to a temperature of about 850 °C (1562 °F) and held thereat for about two hours.
  • Other temperatures and times of the annealing may be used so long as residual stresses are reduced, without producing a change in the microstructure.
  • the temperatures for the annealing are below the liquid phase sintering temperature.
  • the annealed substrate is subjected to resintering according to the teachings of International Patent Application No. PCT/US94/02346.
  • the resintering causes the cobalt to evaporate from the surface of the substrate.
  • the resintering also coarsens the grain size of the tungsten carbide grains at the surface of the substrate so as to roughen the substrate surface.
  • the substrate preferably has a surface roughness of greater than 0.635 mm (25 microinches), R a , and more preferably greater than 0.762 mm (30 microinches), R a , and most preferably at least 1.016 mm (40 microinches), R a .
  • the resintered substrate is then CVD coated with diamond according to the teachings of International Patent Application No. PCT/US94/02346, or any other known CVD diamond coating technology that provides adequate coating adhesion.
  • twist drill of the invention which included the annealing step, were compared to twist drills made by a method that did not have the annealing step therein.
  • the specific style of twist drill was a 8.5 mm diameter TF drill made by Kennametal Hertel AG, of Marieth, Germany. This design has a shank diameter of 10 mm, a shank length of 40 mm, and an overall length of 103 mm.
  • This twist drill has three cutting edges and three flutes.
  • This twist drill has a wall thickness between flutes of about 1.5 mm. The aspect ratio of this drill is, therefore, 103/1.5, or about 69.
  • twist drills of the invention were subjected to the following heat treatments sintering at 1510 °C for three hours; annealing at a temperature of 850 °C for two hours; and resintering at a temperature of 1510 °C for three hours.
  • the comparative twist drills were subjected to the following heat treatments: sintering at 1510 °C for a duration of three hours and resintering at a temperature of 1510 °C for three hours.
  • the drills were hung vertically in the furnace (cutting edge down) during the annealing and resintering treatments.
  • Example 1 15 147 Comparative Example 1 N/A 482
  • Example 2 124 1160 Comparative Example 2 N/A 2022
  • the initial sintered composition of Example 1 and Comparative Example 1 is: about 2.6 weight percent cobalt, up to about 0.4 weight percent tantalum, up to about 0.1 weight percent titanium, up to about 0.1 weight percent niobium, and the balance tungsten and carbon wherein most of the tungsten and carbon is in the form of tungsten carbide and the other elements, if any, may (with tungsten) form solid solution carbides.
  • the initial sintered composition of Example 2 and Comparative Example 2 is about 6 weight percent cobalt, up to about 0.1 weight percent tantalum, up to about 0.1 weight percent titanium, up to about 0.1 weight percent niobium, about 0.2 weight percent vanadium, and the balance tungsten and carbon wherein most of the tungsten and carbon is in the form of tungsten carbide and the other elements, if any, may form solid solution carbides with tungsten.
  • the test results show that in the lower cobalt grade (2.6 weight percent cobalt) the reduction in the run-out due to the anneal was about 70 percent. More specifically, the run-out was reduced from 482 to 147. In the higher cobalt grade (6 weight percent cobalt), the reduction in the run-out was about 40 percent. More specifically, the run-out was reduced from 2022 to 1160.
  • Tests were also conducted to determine if the heating rate of the as-ground substrate from room temperature to the annealing temperature, and if the cooling rate from the annealing temperature to the room temperature, had an impact upon the reduction of the dimensional distortion of the twist drills measured after annealing.
  • the same style of twist drills as used above, a 8.5 mm diameter TF drill were made according to the above method using the annealing step, but for one drill the heating rate from room temperature to the annealing temperature of 850 °C and the cooling rate from the annealing temperature of 850 °C to room temperature was at least 10 °F (5.55°C) per minute and for the other drill the heating and cooling rate was at about 2 °F (1.1°C) per minute.
  • the annealing step and resintering steps could be combined into one step.
  • the annealing treatment would be the first part of this step and the resintering would be the second part of this step.
  • the specific temperatures, durations and atmospheres for the heat treatments and heat up and cool down rates may vary depending upon the specific compositions.
  • the sintering step should consolidate the green body.
  • the annealing step should reduce the residual stresses in the as-ground sintered substrate.
  • the resintering step should evaporate the binder, e.g., cobalt, from, as well as roughen, the surface of the substrate.
  • a slow cooling rate for example, 2 °F/minute (1.1°C/min), or less
  • a slow cooling rate treatment from the resintering temperature may provide sufficient distortion control to make the annealing treatment unnecessary.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Inorganic Chemistry (AREA)
  • Cutting Tools, Boring Holders, And Turrets (AREA)
  • Drilling Tools (AREA)

Claims (12)

  1. Verfahren zur Herstellung eines diamantbeschichteten langgestreckten Schneidelements, welches die folgenden Schritte umfaßt:
    Bereitstellen eines gesinterten Substrats, das durch ein metallisches Bindemittel miteinander verbundene harte Körner umfaßt, wobei ein Anteil des Bindemittels auf der Oberfläche des Substrats vorhanden sein kann;
    Abschleifen von Material von ausgewählten Bereichen des gesinterten Substrats zur Bildung eines wie geschliffen erscheinenden Substrats, das durch das Schleifen verursachte Restspannungen aufweist;
    Glühen des wie geschliffen erscheinenden Substrats bei einer Temperatur unterhalb der Flüssigphasen-Sintertemperatur, um die Restspannungen zu reduzieren und dabei ein geglühtes Substrat zu bilden;
    Nachsintern des geglühten Substrats bei einer Temperatur oberhalb der Flüssigphasen-Sintertemperatur, um die harten Körner auf der Oberfläche des geglühten Substrats gröber zu machen, so daß ein nachgesintertes Substrat mit einer gerauhten Oberfläche gebildet wird; und
    Beschichten des nachgesinterten Substrats mit einem Diamantüberzug durch chemisches Aufdampfen.
  2. Verfahren nach Anspruch 1, bei dem das gesinterte Substrat zwischen 0,2 Gew.-% und 20 Gew.-% Kobalt aufweist.
  3. Verfahren nach Anspruch 1, bei dem das gesinterte Substrat zwischen 0,2 und 2,9 Gew.-% Kobalt, bis zu 0,4 Gew.-% Tantal, bis zu 0,1 Gew.-% Titan, bis zu 0,1 Gew.-% Niob und zum Rest Wolfram und Kohlenstoff aufweist.
  4. Verfahren nach Anspruch 1, bei dem das gesinterte Substrat zwischen 0,2 und 7 Gew.-% Kobalt, bis zu 0,1 Gew.-% Tantal, bis zu 0,1 Gew.-% Titan, bis zu 0,1 Gew.-% Niob, bis zu 0,2 Gew.-% Vanadium und zum Rest Wolfram und Kohlenstoff aufweist.
  5. Verfahren nach einem der Ansprüche 1 bis 4, bei dem das gesinterte Substrat gebildet wird durch Sintern einer verdichteten Pulvermasse bei einer Temperatur zwischen etwa 1400°C und etwa 1600°C und während einer Zeitdauer von etwa zwei Stunden bis etwa drei Stunden.
  6. Verfahren nach einem der Ansprüche 1 bis 5, bei dem das Nachsintern bei einer Temperatur zwischen etwa 1400°C und etwa 1600°C und während einer Zeitdauer von etwa zwei Stunden bis etwa drei Stunden erfolgt.
  7. Verfahren nach einem der Ansprüche 1 bis 6, bei dem die Glühbehandlung bei einer Temperatur von etwa 850 °C und während einer Zeitdauer von etwa 2 Stunden erfolgt.
  8. Verfahren nach einem der Ansprüche 1 bis 7, bei dem das langgestreckte Schneidelement ein Verhältnis von Länge zu Durchmesser (Aspektverhältnis) von größer als 10 hat.
  9. Verfahren nach einem der Ansprüche 1 bis 8, bei dem das nachgesinterte Substrat eine Oberflächenrauhigkeit Ra von mindestens 0,635 mm (25 Mikroinch) hat.
  10. Diamantbeschichtetes langgestrecktes Schneidelement, erhältlich durch ein Verfahren nach einem der Ansprüche 1 bis 9, mit:
    einem Substrat aus einem wolframcarbidhaltigen Sinterhartmetall, das einem Schleifvorgang unterworfen ist, welcher Restspannungen im Substrat erzeugt, gefolgt von einer Glühbehandlung zur Verminderung der Restspannungen, gefolgt von einer Nachsinterung zur Vergröberung der Substratoberfläche;
    wobei das Substrat eine Oberflächenrauhigkeit Ra von mindestens 0,635 mm (25 Mikroinch) hat;
    einem Diamantüberzug auf der Oberfläche des Substrats; und
    wobei das der Glühbehandlung unterworfene Substrat um mindestens 40 Prozent weniger verzogen ist als ein identisches Substrat, das keiner Glühbehandlung unterworfen wurde.
  11. Diamantbeschichtetes langgestrecktes Schneidelement nach Anspruch 10, bei dem das Substrat ein Kobalt-Bindemittel enthält.
  12. Diamantbeschichtetes langgestrecktes Schneidelement nach Anspruch 10, bei dem das Verhältnis von Länge zu Durchmesser (Aspektverhältnis) des Schneidelements größer als 10 ist.
EP97938573A 1996-11-20 1997-08-25 Verfahren zur herstellung eines diamantbeschichteten gegenstandes und dabei erhaltenes produkt Expired - Lifetime EP0950125B1 (de)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US752097 1996-11-20
US08/752,097 US5701578A (en) 1996-11-20 1996-11-20 Method for making a diamond-coated member
PCT/US1997/014924 WO1998022637A1 (en) 1996-11-20 1997-08-25 Method for making a diamond-coated member

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EP0950125A1 EP0950125A1 (de) 1999-10-20
EP0950125B1 true EP0950125B1 (de) 2001-10-24

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US (1) US5701578A (de)
EP (1) EP0950125B1 (de)
JP (1) JP2001504550A (de)
KR (1) KR20000057148A (de)
AU (1) AU724995B2 (de)
DE (2) DE69707707T2 (de)
WO (1) WO1998022637A1 (de)

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CN105382505A (zh) * 2015-12-25 2016-03-09 苏州三骏工具科技有限公司 一种铣刀的加工工艺

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CN105382505A (zh) * 2015-12-25 2016-03-09 苏州三骏工具科技有限公司 一种铣刀的加工工艺

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Publication number Publication date
KR20000057148A (ko) 2000-09-15
JP2001504550A (ja) 2001-04-03
US5701578A (en) 1997-12-23
WO1998022637A1 (en) 1998-05-28
DE69707707D1 (de) 2001-11-29
AU724995B2 (en) 2000-10-05
EP0950125A1 (de) 1999-10-20
DE950125T1 (de) 2000-02-17
DE69707707T2 (de) 2002-08-08
AU4086997A (en) 1998-06-10

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